Fumed Oak Blocks

So this is a finishing project, but it’s made of wood so I’m posting it. I wanted to try my hand at ammonia fuming white oak. I picked up the 28% ammonia at a local retail industrial cleaning supply store. My container is just a clear storage tote I picked up at Lowes. For a better seal, I added an adhesive backed rubber sealing strip. It seals well enough that I can use it in the bathroom with just the exhaust fan running, and I get almost no odor (except when I open it of course). I ran a small heater to keep the temp around 75-80 degrees. I used a single ammonia container that is 6” diameter with about a cup of ammonia.

I used 2 boards to get a feel for how much difference I’d see there. The 1st board (top row in 1st pic) ended up a bit lighter, but probably no big deal. The parts are each labeled with the hours in the container, and ranged from 15 minutes to 48 hrs fuming. After fuming, all of the samples were sealed with Seal-a-cell, the pores filled with antique walnut gel stain, and finished with 2 coats of wipe on urethane. The 0, 36 hr, and 48 hr are left unfinished for comparison.

I was initially quite discouraged when I started pulling samples and they were all a pretty dreary grey. As I applied the finish, however, the brown started to come back thru. Just a couple general notes on the output of the fuming process. 1st – The ray flecks are less pronounced than they are with the stained finishes that I have used. This was the desired outcome of the process as Stickley used it 100 years ago, so should be expected. 2nd – The colors will definitely have a grey tint to them compared to a stained finish. This gives them a softer, or not as bright look. 3rd – The fuming process really penetrates the wood deeply. This gives a much wider “margin of error” when you’re sanding between coats, so that you never need to worry about sanding thru your stain. 4th – Once you’re set up, it’s much easier, cheaper, less messy, and faster than staining.

My preference after fuming a few real pieces (see recently posted clocks) is to only use fuming in the lighter shades, up to about 2 hours or so. In this range, you can get a really nice brownish gray color. Beyond that, the color becomes more and more grey.

Safety notes – 1. Wear gloves (cheap nitrile ones will do) as the stuff irritates the skin, and REALLY burns in the tiniest open cut. 2. Wear sealing goggles, or your eyes WILL get hurt. I was able to use my daughter’s smim goggles, and they worked great. As far as breathing goes, I just held my breath when I opened the container.

I wanted to try fuming recently, but after looking in many shops for ammonia without luck, i was finally told that it’s illegal to sell it here. Apparently too hazardous for Croatians.Looks like yours turned out nicely.

Hi rodneyh!A nice piece of work you’ve done there. I like to ask your permission for the use of your pictures. I’m writing a report for my study on Wood Technologies. Precisely about the molecular process and the modifikation of so treated wood. The pictures and your description match my goal perfectly and i will be happy if i get your allowance to use them.